Columbia University researchers claim millions of HP printers could be open to remote attack via unsecured Remote Firmware Updates. Cybercriminals could steal personal information or attack otherwise secure networks. HP agrees there is a theoretical security problem but says no customer has ever reported unauthorized printer access. The company denies some of the claims and is still investigating others.

MCUs and SoCs have been used in all kinds of equipment since ages.
The real danger lies in tacking on all kinds of unneeded functionality.

Do you need your television to run linux? Should your microwave oven need to run a full OS?
If so, does your microwave oven need to be connected to the cloud? Do you need instant-anywhere food preparation using a fancy html5 webapp? Perhaps a catchy^H^H^Hshitty name will be invented for it such as foodster or snackbook.

This could be somewhat okay, but of course your microwave/dishwasher/hairdryer wants to know what you like on facebook. Perhaps your garage door opener would like to follow you on twitter as well.

This is a massive, partly misguided rant. I admit this, and for this i offer you my apologies.

...

I just think things are going to get a lot worse for our privacy/security.

I suppose just another reflection of the drive to lower overall costs. Not strictly coming from "complicated" or "complex" - in a way quite the contrary, the deal with tightly integrated MCUs & SOCs is, after all, how they ultimately make things massively simpler, on the manufacturing etc. level.

So it starts with basics (essentially a "move" of old functionality into MCU), cheap & simple - but after some time, it's quite straightforward and cheap to add ever more features; additional costs are quickly marginal.

Then it goes further, some "bling" which can draw perhaps a relatively small, but still important group of consumers (especially since this group might be among most eager to buy new stuff, new toys). By that time, it's still only marginally more expensive in production. And it's actually getting less expensive, via economies of scale, to just use the same "complex" unit in essentially entire line of products.